"Mendang" and "Household Pair" are the components of the gate building in the ancient residential buildings, and this kind of architectural decoration used for town houses does not exist much now. The so-called marking, is embedded in the lintel of the hexagonal square wood or log, commonly known as the household pair, if it is a stone door, the marking material is also stone, which is painted with oil paint or pictures according to the grade, or written auspicious blessings and other blessings. These are all manifestations of status, and the popular word "glorious lintel" is actually an intuitive expression of people's yearning for power and wealth.

The lintel is also distinguished, generally according to the number of two, four, and twelve. To put it simply, there are two pairs of households on the lintel, corresponding to the five to seven grade officials; If there are four pairs of households on the lintel, they correspond to officials of more than four grades; As for the twelve household pairs, they can only be used by the prince or above, in other words, even if they are relatives of the emperor and the country, they who are not crowned kings do not dare to build three doors and embed twelve household pairs!

There are also requirements in front of the door, and the officials pay attention to the fact that the door is higher than the road, so there must be steps in front of the door, but this step cannot be repaired casually, and it must be in accordance with the system. The steps in front of the sixth and seventh rank officials cannot be higher than the second level, and the steps in front of the fifth rank official cannot be higher than the third level, and so on, but the number of steps cannot exceed eight steps, and if it exceeds eight levels, it is nine, and nine is the extreme number, which is the number that represents the apex, and no one can use it except the emperor. As officials were promoted, the number of steps in front of the door would slowly increase, and the literati often talked about the term "step to the body", in which the "step" came from.

Door dang, architecturally a part of the "door sleeper stone", commonly known as the door pier, also known as the door seat, the door platform, the door drum, the drum stone with the stone drum, because the drum is grand and majestic, as powerful as thunder, people think that it can avoid ghosts and respect, the people believe that it can avoid evil, so the folk widely use the stone drum on behalf of the "door dang". The household pair is a stone component used for the bottom of the gate of traditional Chinese houses, especially the courtyard house, and plays the role of supporting the door frame and door axis. The gate piers are mainly box-shaped and drum-shaped, but there are also lion-shaped, polygonal columns, bottle-shaped piers and so on. "Mendang", the shape is divided into round and square, the circle is the military attaché, symbolizing the war drum; The square is a civil official, and the shape is an inkstone. The size of the "household pair" is directly proportional to the size of the official product.

A house with a "door" must have a "household pair", which is the principle of harmonious aesthetics in architecture. In this way, "door" and "household" are often called together. Later, it became a common phrase in social concepts to measure the conditions for marriage between men and women.